DE3218812A1 - DEVICE FOR PRODUCING PRINTING PLATES - Google Patents

Description

of the invention: device for producing printing plates

Description:

Devices for the production of printing plates have been known for many years. A horizontally lying slide is used on which the various documents are stored, the images of which are to be transferred to the printing plate and those for transferring the content (images) of the respective document to the printing plate is illuminated. The images are focused on the vertically arranged, photosensitive printing plate in the imaging plane by means of an optical system. After the images have been transferred, the plates are developed and a plate prepared for printing is completed. With some of these devices, large-sized printing plates can be produced, and up to 10,000 prints are possible with such printing plates. However, should such a printing plate have to be used for printing smaller images, then there is a considerable waste. For example, in the 218 "Itek Platemaster ⁿ positive plate production process, an image area of approximately 18x25 inches (45.72 × 63.5 cm) would be exposed on the plate with full utilization of the plate material. The projection of a much smaller

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Image, for example 9 χ 12.6 inches (22.86 χ 32 cm) desired, 30 would be approximately ί | three quarters of the sheet material is not used and would be waste. Furthermore

would be assuming that 40,000 identical prints were made with the printing press are to be produced, four large plates with such a waste proportion, i needed and there would be a corresponding loss of photosensitive

• p material.

y. In this case, the present invention provides the possibility that the 40,000

} ii prints can be made with a large plate without any waste

by showing a device with which a correspondingly large plate is gradually used for correspondingly small images. It is accordingly saved with the invention to a considerable extent plate material, because of

: \ the high cost of the silver component in the film emulsion is very expensive.

,; In order to solve the problem outlined above, consideration has already been given to exposing the

¥ i moving plate in the vertical and horizontal direction so that

i the center point of several partial areas of the plate surface, in particular

i of plate quadrants, is brought into the optical axis of the device.

fe This would be a mask with a section the size of a partial area

ff in particular a plate quadrant is used and so around the optical

! $ Axis of the device adjusted so that only a part of the plate

f | exposed to light. Would use this solution in conjunction with

ψ a large plate making apparatus or machine, so would have to

Il the plate carrier can be adjusted both horizontally and vertically, what

would make the machine heavy and cumbersome, and this would make you too Have considerable space requirements, so that an advantage achieved by yourself

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inevitably adjusting disadvantage would be compensated. In contrast to this In the solution according to the invention, the large printing plate coated with photosensitive material is kept in position during the entire exposure process held stationary in their position, i.e. for several consecutive ones Exposures of individual plate sections while the original document to be imaged or several original documents to be imaged in succession on the original carrier in different positions around the optical axis. In connection with the proposal mentioned above, though adjustable, flat and rectangular mask elements are provided to keep the light away from different areas of the plate carrier. However, this would in connection with the problem to be solved is of no use if with the solution used in the invention is intended to solve the problem.

The present invention thus relates to an apparatus for making printing plates with a photosensitive coating, said apparatus comprising a slide for receiving äes object with the printing plate image to be transmitted, and wherein an optical system as a transmitter of the object contents (image) with the focusing of which is provided on the relatively large, stationary photosensitive printing plate. During the operation of the plate production device, it holds the plate for the duration of the successive transmission of several object contents b;: w. the repeated transfer of the same object content to different areas of the plate in a stationary manner. In addition, according to the teaching of the present invention, a first light blocking mask is associated with the printing plate, which covers approximately one half of this plate and can be moved in a first direction; There is also a second light blocking mask near the printing plate

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assigned to this, which also covers about half of this plate and is to move in a second direction that is transverse to the direction of movement of the ereten light blocking mask. With this arrangement according to the invention <'.. "- possible the different positions of the first and second light blocking masks, different or the same images one after the other on different areas to transfer the printing plate.

In a further embodiment of the invention, a light blocking mask is available as a thin, flat and rectangular plate arranged transversely so that they substantially covers half of the plate surface that is adjacent to the imaging surface, while another light blocking mask is also available as a thin, flat and rectangular one Plate formed, abor is arranged high and also on adjoins the platter surface, which is the imaging surface of the printing plate. Each of these two mask plates is to be steepened in a direction that leads to the direction of movement of the respective other mask plate is perpendicular, so as to enable four different quadrants of the printing plate are formed on which four images can be projected one after another, |

around with the one, relatively large printing plate, four relatively small-area ones, one after the other Perform prints ^ u can.

In a further embodiment of the invention, the adjustment of the transverse arranged mask plate for exposure and consequently transmission of a

Image of or on the right half of the printing plate and after adjustment

■ '' ι the overhead mask plate for exposure and consequently

Transfer of an image of or onto the left half of the printing plate. In ent- k

In a meaningful way, the adjustment of the mask

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plate two superimposed images on the upper and lower half of the plate after removing the transversely arranged mask plate. To Removal of the high-lying Maksenplatte is the same the upper or lower half of the printing plate and after removing both mask plates, a single, correspondingly large image can be applied possible on the entire printing plate surface.

The invention is explained in more detail below with reference to the drawing. In the Show drawing

Fig.l is a representation to explain the prior art and

Fig. 2 + 3 simplified and schematic representation of a solution according to the Invention.

In Figure 1, a vertically aligned photosensitive plate 1 is shown, on to be reproduced by means of an optical system 2 in the printing process Images are to be focused. A horizontally oriented, illuminated slide carries an information carrier on which the images to be focused on the printing plate 1 by means of the system 2 are applied, the term "image" should include all information that can be applied to an information carrier and transmitted on a printing plate, that is to say, in particular, images in their own right Meaning, letters, numbers and other visual symbols used for communication. These images are from the information carrier by means of a Mirror 4 transferred to the projection lens having optical system 2, with which they are then focused on the printing plate 1. Through the mirror image

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The effect of the optical system 2 is the image A in the area 6 of the slide focused on the second plate quadrant 7 of the printing plate. Corresponding an image C on the first quadrant 8, image B on the third quadrant 9 and image D focused on the fourth quadrant 11, as can be seen from FIG.

In accordance with the present invention, an indexing and repeating adapter a first, thin, rectangular and overhead aligned mask plate 12, which is arranged inside irhalb the mask support frame 13, the in turn, is again opposite the photosensitive printing plate 1 at a small distance (FIG. 3). The invention can be made using a very thin transparent plastic plate 14 which forms the rear wall of the mask support frame 13 can be put into practice. Such a thin transparent plate 14 is provided in order to be able to explain the implementation of the invention in the simplest possible way, as easily as possible and as briefly as possible. In the case of implementation of the invention, however, would not put the transparent plastic plate into practice and instead the mask plates would be held at their edges by means which are not the subject of the invention.

The first, high-lying mask plate 12 is a second, transverse arranged thin, flat, rectangular mask plate 16 underlaid, as shown in Figures 2 and 3. According to the invention, the mask plate be moved to the right or left while the masking plate can also be moved, but up or down. These

'{■ Adjustment movements of the mask plates can be carried out by hand,

f | or a conventional cable pull can be provided for this purpose, for example,

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which is assigned an electric drive with limit switches, but what eoll are not explained in more detail, since the drive for adjusting the mask plates is not the subject of the invention. For example, such drives already held by the applicant. The Y drive unit shown schematically in Figure 2 and designated 17 causes the movement of the second mask plate arranged transversely in the horizontal or Y direction. The X-drive unit marked 18 causes the adjustment of the overhead arranged mask plate in the transverse or X direction.

The device works as follows:

It should be assumed that a document as an information carrier has the size of the area A in the section 6 of the slide 3 and that this document is to be transferred to the second quadrant 7 of the printing plate. The overhead mask plate 12 is in the left part of the pressure plate shifted, in the upper area of which the transversely arranged mask plate is shifted (Figure 2). The document on section 6 of the slide is then transferred to the second quadrant 7 by actuating a conventional diaphragm, not shown.

The overhead mask plate 12 is now shifted to the right in order to correspondingly release the quadrant B in section 9 of the printing plate for the recording of the document content, which is now located in the area B of the object recording. The mask plate 16, which is arranged transversely, remains in the upper region of the pressure plate. In the third operating position, the mask plate 12 arranged in the high position remains in the right-hand part of the pressure plate, while the mask plate 16 arranged in the transverse position remains in the lower part

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Area of the pressure plate is moved. It becomes the quadrant D in '

Area 11 of the printing plate is released to display the image of the document>.

to be transferred, which is now in section D of the slide. Closing |>

For the fourth operating position, the mask plate, which is arranged in the upright position, is borrowed 12 moved to the left of the printing plate, while the crosswise arranged mask plate 16 remains in its lower position. It becomes through it section C in area 8 of the printing plate is released in order to display the image on it of the document, which is now in area C of the slide. The document, which is 30 in the various sections or Areas of the slide can be the same document that is repeatedly imaged on the printing plate for large series printing, or it can be different documents that are transferred to the printing plate one after the other for correspondingly smaller print series.

In either case, the result is a quadrupling of the relatively small area Exposure of the printing plate, as opposed to only a transfer of an image with relatively small dimensions, the plate can be used fourfold if it is inserted into a corresponding printing press.

Let us now assume that an even smaller document in the second Quadrant of the printing plate is to be mapped, which for this purpose requires the area A * (Figure 2). The mask plate, which is arranged in a high position, is used for this purpose Shifted to the right until the right edge 21 of the mask plate coincides with the vertical edge 22 of the area A '. In appropriate Way, the transversely arranged mask plate is so wait downwards

pushed until the lower edge 23 of the Maksen plate with the upper edge 24; ·> ■

of area A ¹ coincides. The original A is preferably located here

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of the document in the slide area A 'rather than near the optical axis (Figure 1). In a corresponding way, smaller-format documents can be mapped or transferred to other corner areas of a large printing plate. by sliding the mask plates back in a corresponding manner. However, it is preferable to use small images (smaller than 9 χ 12 inches = 28.8 χ 32.0 cm) located somewhere in the quadrant that is formed by the mask plates in their outermost position inwards or outwards or upwards or downwards. For example, for smaller images in the dimensions 9 χ 12 inches (28.8 χ 32.0 cm) can cause However, the operator can also use sheet material from a narrower roll in order to save material.

It should now be assumed that it is necessary to depict an image on the printing plate which requires the entire lower printing plate area with areas 7 and 9. For this purpose, the mask plate 12 arranged in the high position is completely removed, while the upper region of the pressure plate is covered with the mask plate arranged horizontally. The document to be transferred onto the printing plate is placed on the slide sections A and B. Then the lower area of the printing plate is covered by moving the mask plate 16, which is arranged transversely in the Y-direction, so that a correspondingly large document content on Λ. ι upper printing plate area can be transferred. The pressure plate is used twice. Should it be necessary, Ir iitsprechender way to use the right and left printing plate halves, the transversely arranged mask plate 16 is removed and the remaining high arranged lying mask plate 12 is moved in the X-direction to successively the right and left disc half (or

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vice versa) and also a double use of the pressure plate to enable.

Finally, the entire printing plate area should be used for the one-time illustration a correspondingly large document are required, both mask plates are removed.

One of these versatile uses for adapting to the overhead : ·; The production of documents of different sizes without loss of plate material

Another advantage is that due to the small distance between the

The printing plate and the masking plates do not impair the image quality is to be expected. There is no possibility of plate clouding due to scattering " light. Process in which black or red paint is applied to a cover plate

., - is applied to the slide, as the

| ί paint increasingly lead to scattered light.

In summary, the invention can now be defined again as follows:

% With the invention, a step-by-step and repetitive working adapter

for devices for producing (exposing) large-format printing plates described. With the relatively large printing plate, the simultaneous printing of several small-format images is possible, the smaller-format images Images have been taken one after the other of an object comprising the small-sized images. This means that it can be used multiple times for printing plates possible, which are relatively large in relation to an image, so that light-sensitive material of the printing plates can be saved. One

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first, high, flat, rectangular, blocking the passage of light Mask plate is a short distance in front of the printing plate and is in the transverse direction adjustable. A short distance in front of the printing plate is also a second, the first mask plate corresponding mask plate arranged, the but is arranged transversely and adjustable in the vertical direction. By adjusting know both mask plates against each other and against the pressure plate successively several identical or different small-format images in different Areas of the printing plate are mapped and then reproduced in a printing process. In particular, there should be four small-format Images can be displayed on a correspondingly large printing plate and reproduced when printing. However, one or both of the mask plates are also expandable in order to be able to display a correspondingly smaller number of correspondingly larger images.

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Claims (1)

3219912 J 84 P 118 + GmH Applicant: ITEK CORPORATION, 10 Magulre Road, Lexington, Massachusetts, U.S.A. description j of the invention: device for making printing plates Patent claims: j- 1. Device for the production of printing plates by transferring the to : printing image of an object carrying the image to be printed on a 1: Slide on the photosensitive layer of the printing plate during the Focussing the image on the stationary printing plate in relation to the ; The size of the image to be generated is large, which is why multiple images : · Consecutively or the same figure repeated on different ones Printing plate areas are generated or is characterized by a the (: First mask element (12) blocking the passage of light, the one close to the printing plate ^; ! (1) placed in front of this to cover about half of the printing plate ^: . · And which is adjustable in a first direction (X), marked further ; by a second mask element (16) blocking the passage of light, which ; is also arranged close to the printing plate in front of this, to also about I cover one half of the printing plate and that in a second, for £ <direction of movement of the first mask element perpendicular direction (Y) ί * is adjustable, so that by different positions of the mask elements i J 84 P 118 + GmH β 18th time 1982 - 2 - -2- to each other and to the printing plate on different plate areas successively different images or the same image can or can be transmitted several times. 2. Apparatus according to claim 1, characterized by means (13) which one Allow expansion of at least one of the mask elements (12, 16). 3. Performing according to claim 1 or 2, characterized in that the two Mask elements are thin, flat mask plates (12, 16). 4. Device n <* ch one of claims 1 to 3, characterized in that the relatively large photosensitive printing plate is a relatively large rectangular, photosensitive printing plate (1), wherein the first mask element blocking the passage of light is a rectangular mask plate (12) and the second mask element blocking the passage of light comprises a rectangular mask plate (16). 5. Device according to one of claims 1 to 4, characterized in that the first and the second mask element are each a thin flat sheet (12, 16). 6. Device according to one of claims 1 to 5, wherein the optical imaging system focused on the slide stored images on a large in relation to the images, vertically arranged, light-sensitive printing plate , characterized in that the first mask element blocking the passage of light is a first rectangular, mask plate arranged high J 84 P 118 + GmH May 18, 1982. 3 - * ft · < (12) just in front of the pressure plate, which is about half of the pressure plate f, covered and adjustable in a transverse direction, and that the second is the Mask element blocking the passage of light has a second transverse, rectangular mask plate (16) close to the pressure plate, which is also approximately the Half of the pressure plate is covered and adjustable in a vertical direction, eod that different positions of the two mask plates make it possible to transfer four different or the same images in succession to different sections of the printing plate in order to produce a single printing plate print different or the same images at the same time. J 84 P 118 + GmH May 18, 1982